Improvement in door-springs



' H. B. cose.

Dour-Springs.

Patented Sep.t.8,1874

UNITED STATEs PATENT CEEICE.

HENRY E. COBB, oE WILMINGTON, DELAWARE.

`IMPROVEMENT IN DOOR-SPRINGS.

Specification forming part of Letters Patent No.l 154,840, dated-September 8, 1874; application filed Y May 29, 1874.

To all whom it may concern Beit known that I, `HENRY B. COBB, of Wilmington, in the county of New Castle and State of Delaware, have invented a new and Improved Door-Spring; and I do hereby de- Clare the following to be a full, clear, and exact description thereof, reference being had to the accompanying drawings forming part of this specification, in which- Figure 1 is a perspective View of a door, showing the application of my improved spring. Fig. 2 is a top-plan view, showing the door swung open. Fig. 3 is a side elevation, showing the spring thrown out of operation; and Fig. 4 is a modification, showing an arrangement for the spring for holding the door constantly open.

. Similar letters of reference in the accompa` nying drawings denote the same parts.

My invention has for its object to provide a cheap and effective door-spring for general use; and to this end it consists in the employment of an elliptical steel'spring attached to the door-jamb and suitably connected to the door, so as to open and close the latter easily and without a violent shock, the spring being hinged to the door-jamb and suitably conneeted to the door, for the purpose of closing lmetallic clasps D D. The clasp D is castror otherwise provided with a lug, E, on its outer face, and the clasp D with a pivot or pintle, F, in a similar position.

To apply the spring thus constructed to a` door, the lug of the clasp D is pivoted to a bracket, G, on the side of the door-jamb, so as to hold the spring in an upright position, and by forming a hinge allow it to swing freely. The springis then compressed somewhat, 'so as to exert a pressure of the required strength, and the pivot of the clasp D iuserted in an opening formed in a bracket, H, secured to the side of the door. Before the spring is compressed and attached to .the bracket H, it stands in substantially the position shown in Fig. 3; but after having been compressed and applied to the bracket, it occupies the position substantially as shown in Fig. 1, when the door is closed. As the door is opened the spring also swings on its hinge and is compressedfslightly, so that on releasing the door it shall throw the latter closed, moving it gradually and without a Violent shock. By this construction the torsional action of the spring is avoided, its pressure being exerted directly through the plane of its short axes.

The extreme limit to which the door shall be opened in order to secure the action of the springfor closing it is reached when the hinge and pivot of the spring are thrown into the plane of the door-hinge pintles. If the door is opened beyond this point, the hinge of the' spring is carried inside the plane of the door- -hinge pintles, and the pivot F, forming a leverage equal to the distance the hinge is thrown out of such plane, so that the action of the spring serves to hold the door open, as shown in Fig. 2. v

When it is desired to throw the spring out of action, so that it shall have no effect to close Vor hold the door open, it is compressed by pivot-clasp is reversedthat is to say, applied Y to the spring with its pivot projecting inward. The spring is swung outward so as to stand at right angles, or nearly so, to the door-jamb, being held in this position by any suitable stop or fastening attached to the hinge. The bracket H is turned round so as to carry the projecting portion nearer the outer edge of the door, or it is Set outward toward such edge. The door is then opened and the spring expanded to inclose the bracket, and its pivot inserted in the opening of the latter, as shown in Fig. 4. When the spring is applied in this manner its force is exerted to draw the sides toward each other, and force the door open. The door is closed against the tension of the spring, and since the latter is not allowed to swing on its pivot, it has a certain torsional action, by which its tension is somewhat Aincreased.

Having thus described my invention, what 

